This present invention relates to an improvement in medical and scientific measuring devices, and more particularly to a unique protractor incorporating a `floating point` technology with a clearly defined vertex gap. The present invention, independent of, or in combination with, a plurality of other measuring devices including a centerline finder having a plurality of paired angled lines, each pair of a different color, and intersecting horizontal lines, of a color different from the color of any of the angled lines; and a small-distance discriminator for rapidly locating and measuring small distances at a glance. The device with its various measuring indicia, in combination, provide for a plurality of measurements associated with various technical fields of endeavor and, in the case of health care, for greater precision in measurement of angles, centers, and distances associated with, and necessary for, treatment and care.
In the medical field, and orthopedics in particular, the use of the floating point protractor permits for more accurate measurements and, concomitantly, better pre- and post-operative assessment, treatment, and care. In other technical fields, such as engineering, architecture, and machining, where precision is vital, the floating protractor also permits for greater precision angular accuracy which yields a better final product.
There are a multitude of scientific and technical-related combination devices suited for a variety of scientific and technical applications. U.S. Pat. No. 4,490,921 issued on Jan. 1, 1985, to Woods, discloses a combination drafting tool having a protractor, rulers, a centerline for the rulers, and a plurality of designs thereon. The vertex of the protractor is obscured with a continuous vertical and horizontal line therethrough.
U.S. Pat. No. 4,630,373 issued on Dec. 23, 1986, to Spolyar discloses an apparatus for gauging and determining spatial coordinates for a source of radiation which has a template-like gauge with a first, second, and third plurality of lines and a protractor-like device and a center of revolution (138) situated on the extension of a vertical line (114), said center being a clearly defined circle and without a substantial vertex gap or floating point indicia. In this device, the vertex of the protractor portion is not specifically indicated. Although there is a lack of convergence of the angular lines, the geometric vertex in not indicated. In this device, the `zone of clearance` is quite small in comparison to the floating point configuration of the present invention. This zone makes using and reading quicker and easier. In addition, Spolyar's device refers to the center point as the `center of revolution` to be used for obtaining a reading of the angle of occlusal plane (178). It cannot act independently of the composite device as an angular measuring device.
U.S. Pat. No. 5,033,200 issued on Jul. 23, 1991, to Leung discloses a scientific ruler having a plurality of lenses for use as a telescope, a ruler, an inclined plane adapted to refract sunlight into a rainbow spectrum, a comb, a thermometer, a plurality of mathematic signs, an undulate edge, and a protractor. This device, though comprising a variety of common implements, lacks the floating point technology of the present invention.
U.S. Pat. No. Des. 140,152 issued on Jan. 30, 1945, to Aichele discloses a drawing instrument having, among other features, a protractor. The center point of the protractor has converging horizontal lines, vertical lines, and one diagonal line thereat and is clearly without the floating point and vertex gap of the present invention.
U.S. Pat. No. Des. 322,125 issued on Dec. 3, 1991, to Dorsey (the applicant) discloses a unique design implement adapted to locate centerlines. This device has been found difficult to use, however, without utilizing differently colored lines throughout. Color is an important feature to the function of the present invention as it more easily maintains focus of use. When placing the device on an image which has clearly defined lines, the criss-crossing line pattern of the Dorsey device of the prior art inhibits proper focus. Color associated with the present invention fosters such focus, fosters alignment, and permits for greater discernibility and ease of operation. The present invention also incorporates a centerline and a beveled slot therethrough to facilitate placement of the device and marking.
A standard protractor has one or more converging plot lines meeting at a vertex. Such convergence obscures the vertex, however slightly in some cases, and renders it difficult to see and use for precision measurements. A true vertex is, therefore, more difficult to visualize with the concomitant result of a less-than-true measurement. True measurements are vital to engineering, architectural, scientific, and medical fields of endeavor. A true vertex will yield a true measurement and a better final result. Minute inaccuracies taint and skew results to the detriment of the study, endeavor, or treatment. In the medical field, when treating fractures for example, accuracy of angles--as well as the width of the fracture--is paramount. Slight deviations could affect the post-traumatic assessment and/or post-operative treatment regimen. Accuracy of such measurements leads to improved treatment and care.
None of the prior art devices, alone or in combination, discloses or the floating point technology and vertex gap of the present invention. None, alone or in combination, discloses or teaches a centerline finder structured with a beveled slot and different colored angled lines and different colored horizontal intersecting lines. None, alone or in combination, discloses or teaches a unique small distance discriminator for use in identifying and ascertaining minute separations. Only the present invention provides for the structure of the floating point with its vertex gap and their associated function; and, alone, or in combination with the centerline finder and/or the small distance discriminator provide for a unique functional combination suited for use in the medico-scientific fields of endeavor.
Accordingly, several objects and advantages of my invention are to:
a. facilitate the visualization of the vertex of an angle of interest when using a protractor in its normal sense or in combination with other medico-scientific measuring implements;
b. eliminate the need for guesswork and approximation in identifying a vertex point;
c. accurately and quickly identify and mark a centerline of a long object having symmetric, parallel, and non-parallel sides;
d. accurately and quickly identify minute distances; and
e. provide, in a single device, a plurality of measurement devices which can be operated independently of one another or can interact with one another depending on the user's particular measurement needs.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.